LG recommends not putting a stacked washer and dryer on top of a pedestal. In theory it would work, but I wonder if the pedestal isn't rated to handle that much weight.
Here's what the LG website says in their Q&A section:
"Please EITHER stack an LG Dryer on top of an LG Washer OR put your LG Washer and your LG Dryer on two separate LG Pedestals. It is NOT recommended to stack an LG Dryer on top of an LG Washer which sits on top of an LG Pedestal."